You sometimes read instructions regarding posture for nembutsu. I think this is referring to specific sessions of nembutsu in front of an altar. In this case, a special position for the hands or body can be a way to pay homage, not necessarily a preliminary to do nembutsu. After all, nembutsu is a practice available to us at all times in all places and all situations. This can hardly be limited to one posture.

for use with a rosary, is it ok simply to recite "Amida/Amituofo" while you're not doing your daily practice before the altar/is this common? Read it somewhere but wasn't sure if this was a legitimate practice

for use with a rosary, is it ok simply to recite "Amida/Amituofo" while you're not doing your daily practice before the altar/is this common? Read it somewhere but wasn't sure if this was a legitimate practice

Yes, this is fine. I imagine that this is the only realistic way one can hope for 20,000 repetitions or higher as is recommended by Shan-Tao. I'm not sure he meant for normal people to be sitting in front of their shrines for upwards of 5 hours a day.

Honen on Continuous Recitation wrote:Honen once said, "It’s important that you should never forget the repetition of the nembutsu. Keep it in mind continually. Even though you do impure things or speak impure words, it is a fine thing to keep your heart pure and to say the nembutsu over and over again without stopping it even for a moment. If you go on repeating it at all times and under all circumstances, it will finally bring you to ojo - no doubt about it. Surely don’t imagine that it would be all right to put off the practice of the nembutsu on the grounds that it can be done at any time. On the contrary, don’t let a single moment pass in which you are not practicing it.”

are you supposed to do nembutsu with your eyes open or closed? I usually do it with my eyes closed, as I don't have an image of Amida yet (its coming in the mail soon!). Is it specified one has to do it looking up to Amida? I have heard this is standard but not sure if it really matters.

You can certainly try both. People have reasons for both. My teacher wants us to meditate and do mantras with our eyes open, and I'm extending that to my nembutsu practice as well (although I was doing it already to be honest). It may be easier to concentrate with your eyes closed, but on the other hand people who meditate with their eyes open say it may be easier to bring into your daily life if you keep your eyes open. See what works for you.

As others have said, there are probably many "valid" positions/postures for Nembutsu recitation. For me, comfort comes first so as to do the Nembutsu with fullest attention possible. For me, this is simply sitting in a chair or when going for a walk. I always carry "Buddha beads" in my pocket when I walk, so sometimes if I can find a private/secluded bench to sit on, I'll take out the mala and do a bead-recitation.

I'm semi-disabled, so for me (isn't THAT phrase getting repetitious?) sitting/slowly walking works best because I can't do floor-sitting or anything even close to a lotus posture.